Fuel cell stack water balance test method, device, equipment and medium

Abstract

A fuel cell stack water balance test method, device, equipment, and medium are disclosed, belonging to the field of fuel cell technology. The method includes: while controlling the current output by a proton exchange membrane fuel cell stack to be a reference current, executing the following steps at intervals of a preset duration: reducing the stack operating temperature to reduce the average single-cell voltage; detecting whether the decay rate of the average single-cell voltage reaches a first threshold; if the decay rate of the average single-cell voltage reaches the first threshold, using the stack operating temperature as the water balance critical temperature; and / or executing the following steps: increasing the cathode humidity to reduce the average single-cell voltage; detecting whether the decay rate of the average single-cell voltage reaches a second threshold; if the decay rate of the average single-cell voltage reaches the second threshold, using the cathode humidity and the initial value of the anode humidity as the water balance critical humidity. This application only performs testing under the reference current operating condition, thereby improving test efficiency and reducing test costs.

Description

Technical Field

[0001] The present application relates to the field of fuel cell technology, and in particular to a fuel cell stack water balance testing method, device, equipment and computer-readable storage medium. Background Art

[0002] The conductivity of the proton exchange membrane (PEM) in a proton exchange membrane fuel cell (PEMFC) is closely related to the water content in the fuel cell. Water in the fuel cell originates from two sources: Firstly, to reduce the internal resistance of the fuel cell stack, external water is introduced into the stack by humidifying the reactant gases. This water is then combined with water generated by the cell reactions to ensure adequate membrane wetting. Secondly, because PEMFCs operate at temperatures below 100°C, the water generated by the cell reactions exists in both gas and liquid phases. Liquid water may be present in various locations, including the catalyst layer, diffusion layer, and flow channels. If this liquid water cannot be promptly removed from the stack, it can cause flooding, resulting in reduced catalyst utilization, decreased cell performance, and even corrosion of the electrode materials. Finding the water balance point in the fuel cell stack is crucial.

[0003] In related technologies, a polarization curve test is performed for each preset stack operating temperature or cathode humidity. The stack output current is pulled from a minimum value to a maximum value, and the average cell voltage decay rate is detected to see if it reaches a threshold. The stack operating temperature at which the average cell voltage decay rate reaches the threshold is then used as the critical water balance temperature, or the corresponding cathode humidity is used as the critical water balance humidity.

[0004] However, the set values of the stack operating temperature or cathode humidity are set by relevant personnel based on product characteristics and testing experience. Multiple tests are required to find the water balance point, which results in a long test cycle and high testing costs. Summary of the Invention

[0005] The present application provides a fuel cell stack water balance test method, device, equipment and computer-readable storage medium, which can solve the technical problems in the prior art when determining the water balance point of a fuel cell stack, such as long test cycle and high test cost.

[0006] In a first aspect, an embodiment of the present application provides a fuel cell stack water balance test method, the fuel cell stack water balance test method comprising:

[0007] When the current output by the proton exchange membrane fuel cell stack is controlled to be the reference current, the following steps are performed at intervals of a preset duration:

[0008] Lower the operating temperature of the battery stack to reduce the average single-chip voltage;

[0009] detecting whether the decay rate of the average single-chip voltage reaches a first threshold;

[0010] If the decay rate of the average single-chip voltage reaches a first threshold, obtaining a value of the stack operating temperature, and using the value of the stack operating temperature as the water balance critical temperature;

[0011] and / or,

[0012] When the current output by the proton exchange membrane fuel cell stack is controlled to be the reference current, the following steps are performed at intervals of a preset duration:

[0013] Increase cathode humidity to reduce the average single-chip voltage;

[0014] detecting whether the decay rate of the average single-chip voltage reaches a second threshold;

[0015] If the decay rate of the average single-chip voltage reaches a second threshold, the value of the cathode humidity is obtained, and the value of the cathode humidity and the initial value of the anode humidity are used as the water balance critical humidity.

[0016] In combination with the first aspect, in one embodiment, after the step of detecting whether the decay rate of the average single-chip voltage reaches the first threshold, the method further includes:

[0017] If the decay rate of the average single-chip voltage does not reach the first threshold, determining whether the operating time reaches a preset time;

[0018] If the operating time reaches the preset time, return to the step of lowering the operating temperature of the fuel cell stack;

[0019] If the running time does not reach the preset time, the process returns to the step of detecting whether the decay rate of the average single-chip voltage reaches the first threshold.

[0020] In combination with the first aspect, in one embodiment, after the step of detecting whether the decay rate of the average single-chip voltage reaches the second threshold, the method further includes:

[0021] If the decay rate of the average single-chip voltage does not reach the second threshold, detecting whether the cathode humidity has reached a saturation value;

[0022] If the cathode humidity has not reached the saturation value, determine whether the operating time has reached the preset time;

[0023] If the running time reaches the preset time, return to the step of increasing the cathode humidity;

[0024] If the running time does not reach the preset time, the process returns to the step of detecting whether the decay rate of the average single-chip voltage reaches the second threshold.

[0025] In combination with the first aspect, in one embodiment, after the step of detecting whether the decay rate of the average single-chip voltage reaches the second threshold, the method further includes:

[0026] If the decay rate of the average single-chip voltage does not reach the second threshold, detecting whether the cathode humidity has reached a saturation value;

[0027] If the cathode humidity reaches the saturation value, the anode humidity is increased to reduce the average single-chip voltage;

[0028] detecting whether the decay rate of the average single-chip voltage reaches a third threshold;

[0029] If the decay rate of the average single-chip voltage reaches a third threshold, the value of the anode humidity is obtained, and the value of the anode humidity and the saturation value of the cathode humidity are used as the water balance critical humidity.

[0030] In combination with the first aspect, in one embodiment, after the step of detecting whether the decay rate of the average single-chip voltage reaches the third threshold, the method further includes:

[0031] If the decay rate of the average single-chip voltage does not reach the third threshold, detecting whether the anode humidity has reached a saturation value;

[0032] If the anode humidity has not reached the saturation value, determine whether the operating time has reached the preset time;

[0033] If the running time reaches the preset time, return to the step of increasing the anode humidity;

[0034] If the running time does not reach the preset time, the process returns to the step of detecting whether the decay rate of the average single-chip voltage reaches the third threshold.

[0035] In combination with the first aspect, in one embodiment, after the step of detecting whether the decay rate of the average single-chip voltage reaches the third threshold, the method further includes:

[0036] If the decay rate of the average single-chip voltage does not reach the third threshold, detecting whether the anode humidity has reached a saturation value;

[0037] If the anode humidity reaches the saturation value, the cathode stoichiometric ratio is reduced to reduce the average single-chip voltage;

[0038] detecting whether the decay rate of the average single-chip voltage reaches a fourth threshold;

[0039] If the decay rate of the average single-chip voltage reaches a fourth threshold, the saturation value of the cathode humidity and the saturation value of the anode humidity are used as the water balance critical humidity.

[0040] In a second aspect, an embodiment of the present application provides a fuel cell stack water balance test device, the fuel cell stack water balance test device comprising:

[0041] The first execution module is configured to, while controlling the current output by the proton exchange membrane fuel cell stack to be a reference current, execute the following steps at intervals of a preset duration: lowering the stack operating temperature to reduce the average single-cell voltage; detecting whether the decay rate of the average single-cell voltage reaches a first threshold; if the decay rate of the average single-cell voltage reaches the first threshold, obtaining a value of the stack operating temperature, and using the value of the stack operating temperature as a water balance critical temperature;

[0042] and / or,

[0043] The second execution module is used to perform the following steps at each preset time interval while controlling the current output by the proton exchange membrane fuel cell stack to be a reference current: increasing the cathode humidity to reduce the average single-chip voltage; detecting whether the attenuation rate of the average single-chip voltage reaches a second threshold; if the attenuation rate of the average single-chip voltage reaches the second threshold, obtaining the numerical value of the cathode humidity, and using the numerical value of the cathode humidity and the initial value of the anode humidity as the water balance critical humidity.

[0044] In combination with the second aspect, in one embodiment, the fuel cell stack water balance test device also includes a first detection module, which is specifically used to, after the step of detecting whether the attenuation rate of the average single-chip voltage reaches a first threshold, if the attenuation rate of the average single-chip voltage does not reach the first threshold, determine whether the operating time reaches a preset time; if the operating time reaches the preset time, return to the step of lowering the stack operating temperature; if the operating time does not reach the preset time, return to the step of detecting whether the attenuation rate of the average single-chip voltage reaches the first threshold.

[0045] In a third aspect, an embodiment of the present application provides a fuel cell stack water balance test device, which includes a processor, a memory, and a fuel cell stack water balance test program stored in the memory and executable by the processor, wherein when the fuel cell stack water balance test program is executed by the processor, the steps of the fuel cell stack water balance test method as described in any one of the first aspects are implemented.

[0046] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, on which a fuel cell stack water balance test program is stored, wherein when the fuel cell stack water balance test program is executed by a processor, the steps of the fuel cell stack water balance test method as described in any one of the first aspects are implemented.

[0047] The beneficial effects of the technical solutions provided in the embodiments of the present application include:

[0048] By controlling the current output by the proton exchange membrane fuel cell stack to be a reference current, the following steps are performed at each preset time interval: lowering the stack operating temperature to reduce the average single-chip voltage; detecting whether the attenuation rate of the average single-chip voltage reaches a first threshold; if the attenuation rate of the average single-chip voltage reaches the first threshold, obtaining the value of the stack operating temperature, and using the value of the stack operating temperature as the water balance critical temperature; and / or, controlling the current output by the proton exchange membrane fuel cell stack to be a reference current, the following steps are performed at each preset time interval: increasing the cathode humidity to reduce the average single-chip voltage; detecting whether the attenuation rate of the average single-chip voltage reaches a second threshold; if the attenuation rate of the average single-chip voltage reaches the second threshold, obtaining the value of the cathode humidity, and using the value of the cathode humidity and the initial value of the anode humidity as the water balance critical humidity. This application is only tested under the reference current condition, which can meet the stack performance attenuation judgment benchmark for most products, improves test efficiency, and reduces test costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 This is a flow chart of the first embodiment of the fuel cell stack water balance test method of the present application;

[0050] Figure 2 This is a schematic diagram of the functional modules of an embodiment of a fuel cell stack water balance test device of the present application;

[0051] Figure 3 This is a schematic diagram of the hardware structure of the fuel cell stack water balance test equipment involved in the embodiment of the present application. DETAILED DESCRIPTION

[0052] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0053] The generation of liquid water inside the proton exchange membrane fuel cell stack involves two variables, one is the humidity of the reaction gas after humidification, and the other is the stack operating temperature. It can be understood that when the stack operating temperature remains unchanged, the higher the humidity of the reaction gas, the more liquid water is generated; when the humidity of the reaction gas remains unchanged, the lower the stack operating temperature, the more liquid water is generated. When the liquid water reaches the critical point of the stack water balance, it will affect the output of the stack performance. The critical point of the stack water balance is when "water flooding" begins to occur inside the stack, which manifests as a decay in the electric propulsion output performance. The present application adjusts the stack operating temperature and / or cathode humidity at the reference current output operating point in the polarization curve operating point, and combines some current standard requirements to formulate a stack performance decay judgment benchmark that can meet the needs of most products, and can quickly and effectively determine the critical temperature point and / or critical humidity point of the fuel cell stack water balance.

[0054] It is understood that before executing the fuel cell stack water balance test method described in this application, it is necessary to first complete the activation test of the proton exchange membrane fuel cell stack to stabilize the stack performance. The polarization curve test is then performed on the activated proton exchange membrane fuel cell stack. During the test, only the baseline current operating condition needs to be continuously maintained. The baseline current is the current corresponding to an average single-cell voltage of 0.7V.

[0055] In order to make the objectives, technical solutions and advantages of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0056] In a first aspect, an embodiment of the present application provides a method for testing water balance of a fuel cell stack.

[0057] In one embodiment, referring to Figure 1 , Figure 1 This is a flow chart of the first embodiment of the fuel cell stack water balance test method of this application. Figure 1 As shown, the fuel cell stack water balance test method includes:

[0058] When the current output by the proton exchange membrane fuel cell stack is controlled to be the reference current, the following steps are performed at intervals of a preset duration:

[0059] Step 110: Lowering the operating temperature of the stack to reduce the average single-chip voltage;

[0060] It should be noted that fuel cell suppliers pre-select multiple operating points, which are the current output by the stack. For example, 10 operating points may be selected between 0 and 100A, namely 10A, 20A, 30A, 90A, and 100A. Initial values for the relevant parameters corresponding to each operating point are calibrated. These parameters include, but are not limited to, cooling air supply, hydrogen-to-air stoichiometric ratio, cathode humidity, anode humidity, pressure, and stack operating temperature.

[0061] To control the PEM fuel cell stack output current to the baseline current, it is necessary to obtain initial values for parameters related to the baseline current operating point. Entering these initial values into the stack test bench will ensure the PEM fuel cell stack output current is maintained at the baseline current. Maintaining the PEM fuel cell stack output current at the baseline current is maintained for 3 minutes.

[0062] Among them, the preset time length can be flexibly set according to actual needs, and this application does not make specific restrictions on this. For the convenience of description, the preset time length is selected as 3 minutes to introduce this application.

[0063] In specific implementation, the initial value of the stack operating temperature is obtained from the stack test bench. Based on the initial value, the stack operating temperature is lowered and the operating time is recalculated. As the stack operating temperature decreases, the average single-chip voltage also decreases. Preferably, the temperature is lowered by 1°C at a time to prevent the opportunity to determine the critical water balance temperature from being missed due to excessive reductions.

[0064] It should be noted that only the operating temperature of the fuel cell stack is lowered, and the initial values of other parameters remain unchanged.

[0065] Step 120: Detect whether the decay rate of the average single-chip voltage reaches a first threshold;

[0066] The decay rate of the average single-chip voltage under the reference current is the key criterion for evaluating the performance decay of the battery stack. Among them, the first threshold of the decay rate can be flexibly set according to actual needs, and this application does not make specific restrictions on this. Referring to the 10% decay rate specified in the relevant standards as the evaluation benchmark, that is, the average single-chip voltage is reduced to 90% of the reference voltage (0.7V), that is, it is reduced to 0.63V. The following is an introduction taking the first threshold of 10% as an example.

[0067] In a specific implementation, after lowering the operating temperature of the battery stack, it is detected whether the attenuation rate of the average single-chip voltage reaches 10%.

[0068] Step 130: If the decay rate of the average single-chip voltage reaches a first threshold, obtain the value of the stack operating temperature, and use the value of the stack operating temperature as the water balance critical temperature;

[0069] When the average single-cell voltage decay rate reaches 10%, it indicates that "water flooding" has just begun to form inside the stack. The corresponding stack operating temperature at this time is the critical water balance temperature. Therefore, the stack operating temperature value is obtained from the stack test bench. The obtained stack operating temperature value is the reduced value and is used as the critical water balance temperature.

[0070] It can be understood that restoring the stack operating conditions to the initial set values, and after the stack performance stabilizes, repeating steps 110 to 130 multiple times to determine multiple water balance critical temperatures and then taking the average value can improve the accuracy of determining the water balance critical temperature.

[0071] and / or,

[0072] When the current output by the proton exchange membrane fuel cell stack is controlled to be the reference current, the following steps are performed at intervals of a preset duration:

[0073] Step 140: increasing the cathode humidity to reduce the average single-chip voltage;

[0074] In practice, the initial cathode humidity value is obtained from the stack test bench. Based on this initial value, the cathode humidity is increased and the run time is recalculated. As the cathode humidity increases, the average single-cell voltage decreases. Preferably, the cathode humidity is increased by 5% at a time to prevent excessive increases that could result in missing the critical water balance humidity.

[0075] It should be noted that only the cathode humidity is increased, and the initial values of other parameters remain unchanged.

[0076] Step 150: Detect whether the decay rate of the average single-chip voltage reaches a second threshold;

[0077] It should be noted that the first threshold, the second threshold, and the third and fourth thresholds described below may be the same. The following description will still be made by taking the above four thresholds as 10% as an example.

[0078] In a specific implementation, after increasing the humidity of the cathode, it is detected whether the attenuation rate of the average single-chip voltage reaches 10%.

[0079] Step 160: If the decay rate of the average single-chip voltage reaches a second threshold, obtain the value of the cathode humidity, and use the value of the cathode humidity and the initial value of the anode humidity as the water balance critical humidity.

[0080] When the average cell voltage decay rate reaches 10%, it indicates that water flooding has just begun to form inside the stack. The corresponding cathode and anode humidity at this point are the critical water balance humidity. Therefore, the cathode humidity value obtained from the stack test bench is amplified, and this cathode humidity value and the initial anode humidity value are used as the critical water balance humidity.

[0081] It can be understood that after the operating conditions of the battery stack are restored to the initial set values and the performance of the battery stack is stabilized, steps 140 to 160 can be repeated multiple times to determine multiple water balance critical humidity values, and then the average value is taken, which can improve the accuracy of determining the water balance critical humidity value.

[0082] It should be noted that this embodiment includes three cases. The first case is to only execute steps 110 to 130 to determine the water balance critical temperature. The second case is to only execute steps 140 to 160 to determine the water balance critical humidity. The third case is to execute steps 110 to 130 to determine the water balance critical temperature and steps 140 to 160 to determine the water balance critical humidity.

[0083] In this embodiment, by controlling the current output by the proton exchange membrane fuel cell stack to be a reference current, the following steps are performed at each preset time interval: lowering the stack operating temperature to reduce the average single-chip voltage; detecting whether the attenuation rate of the average single-chip voltage reaches a first threshold; if the attenuation rate of the average single-chip voltage reaches the first threshold, obtaining the value of the stack operating temperature, and using the value of the stack operating temperature as the water balance critical temperature; and / or, by controlling the current output by the proton exchange membrane fuel cell stack to be a reference current, the following steps are performed at each preset time interval: increasing the cathode humidity to reduce the average single-chip voltage; detecting whether the attenuation rate of the average single-chip voltage reaches a second threshold; if the attenuation rate of the average single-chip voltage reaches the second threshold, obtaining the value of the cathode humidity, and using the value of the cathode humidity and the initial value of the anode humidity as the water balance critical humidity. This application is only tested under the reference current condition, which can meet the stack performance attenuation judgment benchmark for most products, improves test efficiency, and reduces test costs.

[0084] Furthermore, in one embodiment, after the step of detecting whether the decay rate of the average single-chip voltage reaches the first threshold, the method further includes:

[0085] Step 210: If the decay rate of the average single-chip voltage does not reach the first threshold, determine whether the operating time reaches a preset time;

[0086] Step 220: If the operating time reaches the preset time, return to the step of lowering the operating temperature of the fuel cell stack;

[0087] Step 230: If the running time does not reach the preset time, return to the step of detecting whether the decay rate of the average single-chip voltage reaches the first threshold.

[0088] In specific implementations, if the average single-chip voltage decay rate is detected to be less than 10%, it indicates that the stack operating temperature is insufficient to convert gaseous water into liquid water, and the stack operating temperature needs to be further lowered. A further determination is made as to whether the operating time has reached 3 minutes. If so, the process returns to step 110 to continue lowering the stack operating temperature to further reduce the average single-chip voltage and recalculate the operating time. If the operating time has not reached 3 minutes, the process returns to step 120 to determine whether the average single-chip voltage decay rate has reached the first threshold.

[0089] In this embodiment, after the step of detecting whether the attenuation rate of the average single-chip voltage reaches the first threshold, the step also includes judging whether the operating time reaches the preset time if the attenuation rate of the average single-chip voltage does not reach the first threshold; if the operating time reaches the preset time, returning to the step of lowering the operating temperature of the battery stack; if the operating time does not reach the preset time, returning to the step of detecting whether the attenuation rate of the average single-chip voltage reaches the first threshold, and gradually lowering the operating temperature of the battery stack through a cycle to achieve the purpose of gradually lowering the average single-chip voltage until the attenuation rate of the average single-chip voltage reaches the first threshold.

[0090] Furthermore, in one embodiment, after the step of detecting whether the decay rate of the average single-chip voltage reaches the second threshold, the method further includes:

[0091] Step 310: If the decay rate of the average single-chip voltage does not reach the second threshold, detect whether the cathode humidity reaches the saturation value;

[0092] Step 320: If the cathode humidity has not reached the saturation value, determine whether the operating time has reached the preset time;

[0093] Step 330: If the running time reaches the preset time, return to the step of increasing the cathode humidity;

[0094] Step 340: If the running time does not reach the preset time, return to the step of detecting whether the decay rate of the average single-chip voltage reaches the second threshold.

[0095] Generally speaking, the saturation value of the cathode humidity and the saturation value of the anode humidity are both 100%. The following description takes the saturation value of 100% as an example.

[0096] In specific implementations, if the average single-chip voltage decay rate does not reach 10%, the cathode humidity is checked to see if it has reached 100%, thereby determining whether to continue increasing the cathode humidity or the anode humidity. If the cathode humidity does not reach 100%, this indicates that the cathode humidity is insufficient to convert gaseous water into liquid water, and further increasing the cathode humidity is necessary. A further determination is made as to whether the operating time has reached 3 minutes. If the operating time has reached 3 minutes, the process returns to the step of increasing the cathode humidity, i.e., step 140, to continue increasing the cathode humidity to further reduce the average single-chip voltage and recalculate the operating time. If the operating time has not reached 3 minutes, the process returns to the step of detecting whether the average single-chip voltage decay rate has reached a second threshold, i.e., returning to step 150 for continued testing.

[0097] In this embodiment, after the step of detecting whether the attenuation rate of the average single-chip voltage reaches the second threshold, the step also includes detecting whether the cathode humidity reaches the saturation value if the attenuation rate of the average single-chip voltage does not reach the second threshold; if the cathode humidity does not reach the saturation value, judging whether the operating time reaches the preset time; if the operating time reaches the preset time, returning to the step of increasing the cathode humidity; if the operating time does not reach the preset time, returning to the step of detecting whether the attenuation rate of the average single-chip voltage reaches the second threshold, and gradually increasing the cathode humidity through a cycle to achieve the purpose of gradually reducing the average single-chip voltage until the attenuation rate of the average single-chip voltage reaches the second threshold.

[0098] Furthermore, in one embodiment, after the step of detecting whether the decay rate of the average single-chip voltage reaches the second threshold, the method further includes:

[0099] Step 410: If the decay rate of the average single-chip voltage does not reach the second threshold, detect whether the cathode humidity reaches the saturation value;

[0100] Step 420: If the cathode humidity reaches the saturation value, then increase the anode humidity to reduce the average single-chip voltage;

[0101] Step 430: Detect whether the decay rate of the average single-chip voltage reaches a third threshold;

[0102] Step 440: If the decay rate of the average single-chip voltage reaches a third threshold, the value of the anode humidity is obtained, and the value of the anode humidity and the saturation value of the cathode humidity are used as the water balance critical humidity.

[0103] In specific implementation, if the attenuation rate of the average single-chip voltage does not reach 10%, the cathode humidity is detected to see if it has reached 100%, so as to determine whether the cathode humidity should continue to be increased or the anode humidity should be increased; if the cathode humidity reaches 100%, it indicates that there is no room for further increase in the cathode humidity. At this time, the anode humidity needs to be increased to further reduce the average single-chip voltage and recalculate the operating time; preferably, the anode humidity is increased by 5% each time to prevent the opportunity to determine the critical humidity of water balance from being missed due to the large increase span.

[0104] After increasing the anode humidity, the average cell voltage decay rate is further tested to see if it reaches 10%. When the average cell voltage decay rate reaches 10%, it indicates that "water flooding" has just begun to occur inside the stack. The corresponding cathode humidity and anode humidity at this time are the critical water balance humidity. At this time, the cathode humidity is at a saturated value. The anode humidity value obtained directly from the stack test bench is the increased value. The anode humidity value and the saturated value of the cathode humidity are used as the critical water balance humidity.

[0105] In this embodiment, after the step of detecting whether the attenuation rate of the average single-chip voltage reaches the second threshold, the step also includes detecting whether the cathode humidity reaches the saturation value if the attenuation rate of the average single-chip voltage does not reach the second threshold; if the cathode humidity reaches the saturation value, increasing the anode humidity to reduce the average single-chip voltage; detecting whether the attenuation rate of the average single-chip voltage reaches the third threshold; if the attenuation rate of the average single-chip voltage reaches the third threshold, obtaining the value of the anode humidity, and using the value of the anode humidity and the saturation value of the cathode humidity as the water balance critical humidity, and gradually increasing the anode humidity through a cycle to achieve the purpose of gradually reducing the average single-chip voltage until the attenuation rate of the average single-chip voltage reaches the third threshold.

[0106] Furthermore, in one embodiment, after the step of detecting whether the decay rate of the average single-chip voltage reaches the third threshold, the method further includes:

[0107] Step 510: If the decay rate of the average single-chip voltage does not reach the third threshold, detect whether the anode humidity reaches a saturation value;

[0108] Step 520: If the anode humidity has not reached the saturation value, determine whether the operating time has reached the preset time;

[0109] Step 530: If the running time reaches the preset time, return to the step of increasing the anode humidity;

[0110] Step 540: If the running time does not reach the preset time, return to the step of detecting whether the decay rate of the average single-chip voltage reaches the third threshold.

[0111] In specific implementations, if the average cell voltage decay rate is detected to be less than 10%, the anode humidity is checked to see if it has reached 100%, thereby determining whether to continue increasing the anode humidity or reduce the cathode stoichiometric ratio. If the anode humidity is less than 100%, this indicates that the anode humidity is insufficient to convert gaseous water into liquid water, and further increasing the anode humidity is necessary. A further determination is made as to whether the run time has reached 3 minutes. If so, the process returns to the step of increasing the anode humidity to further reduce the average cell voltage and recalculate the run time. If not, the process returns to the step of checking whether the average cell voltage decay rate has reached 10% and continues testing.

[0112] In this embodiment, after the step of detecting whether the attenuation rate of the average single-chip voltage reaches the third threshold, the step also includes detecting whether the anode humidity reaches the saturation value if the attenuation rate of the average single-chip voltage does not reach the third threshold; if the anode humidity does not reach the saturation value, judging whether the operating time reaches the preset time; if the operating time reaches the preset time, returning to the step of increasing the anode humidity; if the operating time does not reach the preset time, returning to the step of detecting whether the attenuation rate of the average single-chip voltage reaches the third threshold, and gradually increasing the anode humidity through a cycle to achieve the purpose of gradually reducing the average single-chip voltage until the attenuation rate of the average single-chip voltage reaches the third threshold.

[0113] Furthermore, in one embodiment, after the step of detecting whether the decay rate of the average single-chip voltage reaches the third threshold, the method further includes:

[0114] Step 610: If the decay rate of the average single-chip voltage does not reach the third threshold, detect whether the anode humidity reaches a saturation value;

[0115] Step 620: If the anode humidity reaches the saturation value, reduce the cathode stoichiometric ratio to reduce the average single-chip voltage;

[0116] Step 530: Detect whether the decay rate of the average single-chip voltage reaches a fourth threshold;

[0117] Step 540: If the decay rate of the average single-chip voltage reaches a fourth threshold, the saturation value of the cathode humidity and the saturation value of the anode humidity are used as the water balance critical humidity.

[0118] During specific implementation, if the attenuation rate of the average single-chip voltage does not reach the third threshold value, the anode humidity is detected to see if it has reached 100%, so as to determine whether the anode humidity should continue to be increased or the cathode metering ratio should be reduced; if the anode humidity reaches 100%, it indicates that there is no room for further increase in the anode humidity, and the cathode metering ratio needs to be reduced at this time to further reduce the average single-chip voltage and recalculate the operating time; preferably, the cathode metering ratio is reduced by 10% each time.

[0119] After reducing the cathode stoichiometric ratio, the average cell voltage decay rate is further tested to see if it reaches 10%. When the average cell voltage decay rate reaches 10%, it indicates that "water flooding" has just begun to occur within the stack. The corresponding cathode and anode humidity at this time are the critical water balance humidity. At this time, the cathode and anode humidity are both saturated, so the saturated values of the cathode and anode humidity are used as the critical water balance humidity.

[0120] In this embodiment, after the step of detecting whether the attenuation rate of the average single-chip voltage reaches the third threshold, it also includes: if the attenuation rate of the average single-chip voltage does not reach the third threshold, detecting whether the anode humidity reaches the saturation value; if the anode humidity reaches the saturation value, reducing the cathode stoichiometric ratio to reduce the average single-chip voltage; detecting whether the attenuation rate of the average single-chip voltage reaches the fourth threshold; if the attenuation rate of the average single-chip voltage reaches the fourth threshold, using the saturation value of the cathode humidity and the saturation value of the anode humidity as the water balance critical humidity, and gradually reducing the cathode stoichiometric ratio through a cycle to achieve the purpose of gradually reducing the average single-chip voltage until the attenuation rate of the average single-chip voltage reaches the fourth threshold.

[0121] In a second aspect, an embodiment of the present application also provides a fuel cell stack water balance testing device.

[0122] In one embodiment, referring to Figure 2 , Figure 2 This is a functional module diagram of an embodiment of a fuel cell stack water balance test device of the present application. Figure 2 As shown, the fuel cell stack water balance test device 200 includes:

[0123] The first execution module 210 is configured to, while controlling the current output by the proton exchange membrane fuel cell stack to be a reference current, execute the following steps at intervals of a preset duration: lowering the stack operating temperature to reduce the average single-cell voltage; detecting whether the decay rate of the average single-cell voltage reaches a first threshold; if the decay rate of the average single-cell voltage reaches the first threshold, obtaining a value of the stack operating temperature, and using the value of the stack operating temperature as a water balance critical temperature;

[0124] and / or,

[0125] The second execution module 220 is used to perform the following steps at each preset time interval while controlling the current output by the proton exchange membrane fuel cell stack to be a reference current: increasing the cathode humidity to reduce the average single-chip voltage; detecting whether the attenuation rate of the average single-chip voltage reaches a second threshold; if the attenuation rate of the average single-chip voltage reaches the second threshold, obtaining the value of the cathode humidity, and using the value of the cathode humidity and the initial value of the anode humidity as the water balance critical humidity.

[0126] Furthermore, in one embodiment, the fuel cell stack water balance test device also includes a first detection module, which is specifically used to, after the step of detecting whether the attenuation rate of the average single-chip voltage reaches a first threshold, determine whether the operating time reaches a preset time if the attenuation rate of the average single-chip voltage does not reach the first threshold; if the operating time reaches the preset time, return to the step of lowering the stack operating temperature; if the operating time does not reach the preset time, return to the step of detecting whether the attenuation rate of the average single-chip voltage reaches the first threshold.

[0127] Furthermore, in one embodiment, the fuel cell stack water balance test device also includes a second detection module, which is specifically used to detect whether the cathode humidity has reached a saturation value after the step of detecting whether the attenuation rate of the average single-chip voltage has reached a second threshold value, if the attenuation rate of the average single-chip voltage has not reached the second threshold value; if the cathode humidity has not reached the saturation value, determine whether the operating time has reached a preset time length; if the operating time has reached the preset time length, return to the step of increasing the cathode humidity; if the operating time has not reached the preset time length, return to the step of detecting whether the attenuation rate of the average single-chip voltage has reached the second threshold value.

[0128] Furthermore, in one embodiment, the fuel cell stack water balance test device also includes a third detection module, which is specifically used to detect whether the cathode humidity has reached a saturation value after the step of detecting whether the attenuation rate of the average single-chip voltage has reached a second threshold value, if the attenuation rate of the average single-chip voltage has not reached the second threshold value; if the cathode humidity has reached the saturation value, increase the anode humidity to reduce the average single-chip voltage; detect whether the attenuation rate of the average single-chip voltage has reached a third threshold value; if the attenuation rate of the average single-chip voltage has reached the third threshold value, obtain the value of the anode humidity, and use the value of the anode humidity and the saturation value of the cathode humidity as the critical humidity for water balance.

[0129] Furthermore, in one embodiment, the fuel cell stack water balance test device also includes a fourth detection module, which is specifically used to detect whether the anode humidity has reached a saturation value after the step of detecting whether the attenuation rate of the average single-chip voltage has reached a third threshold value, if the attenuation rate of the average single-chip voltage has not reached the third threshold value; if the anode humidity has not reached the saturation value, determine whether the operating time has reached a preset time; if the operating time has reached the preset time, return to the step of increasing the anode humidity; if the operating time has not reached the preset time, return to the step of detecting whether the attenuation rate of the average single-chip voltage has reached the third threshold value.

[0130] Furthermore, in one embodiment, the fuel cell stack water balance test device also includes a fifth detection module, which is specifically used to detect whether the anode humidity has reached a saturation value after the step of detecting whether the attenuation rate of the average single-chip voltage has reached a third threshold value, if the attenuation rate of the average single-chip voltage has not reached the third threshold value; if the anode humidity has reached the saturation value, reduce the cathode metering ratio to reduce the average single-chip voltage; detect whether the attenuation rate of the average single-chip voltage has reached a fourth threshold value; if the attenuation rate of the average single-chip voltage has reached the fourth threshold value, use the saturation value of the cathode humidity and the saturation value of the anode humidity as the critical humidity for water balance.

[0131] Among them, the functional implementation of each module in the above-mentioned fuel cell stack water balance test device corresponds to the various steps in the above-mentioned fuel cell stack water balance test method embodiment, and their functions and implementation processes will not be repeated here one by one.

[0132] In a third aspect, an embodiment of the present application provides a fuel cell stack water balance test device, which may be a personal computer (PC), a laptop computer, a server, or other device with data processing capabilities.

[0133] Reference Figure 3 , Figure 3 Schematic diagram of the hardware structure of the fuel cell stack water balance test device involved in the embodiment of the present application. In the embodiment of the present application, the fuel cell stack water balance test device may include a processor, a memory, a communication interface and a communication bus.

[0134] The communication bus may be of any type and is used to interconnect the processor, memory, and communication interface.

[0135] Communication interfaces include input / output (I / O) interfaces, physical interfaces, and logical interfaces, used to interconnect components within the fuel cell stack water balance test equipment, as well as interfaces used to interconnect the fuel cell stack water balance test equipment with other devices (such as other computing devices or user devices). Physical interfaces can include Ethernet interfaces, fiber optic interfaces, ATM interfaces, etc.; user devices can include displays, keyboards, etc.

[0136] The memory can be various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical storage, hard disk, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.

[0137] The processor may be a general-purpose processor, which may call a fuel cell stack water balance test program stored in a memory and execute the fuel cell stack water balance test method provided in an embodiment of the present application. For example, the general-purpose processor may be a central processing unit (CPU). The method executed when the fuel cell stack water balance test program is called may refer to the various embodiments of the fuel cell stack water balance test method of the present application, and will not be repeated here.

[0138] Those skilled in the art will understand that Figure 3 The hardware structure shown in the figure does not constitute a limitation to the present application and may include more or fewer components than shown in the figure, or a combination of certain components, or a different arrangement of components.

[0139] In a fourth aspect, an embodiment of the present application also provides a computer-readable storage medium.

[0140] The computer-readable storage medium of the present application stores a fuel cell stack water balance test program, wherein when the fuel cell stack water balance test program is executed by a processor, the steps of the fuel cell stack water balance test method as described above are implemented.

[0141] Among them, the method implemented when the fuel cell stack water balance test program is executed can refer to the various embodiments of the fuel cell stack water balance test method of this application, and will not be repeated here.

[0142] It should be noted that the serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0143] The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices. The terms "first", "second" and "third" are used to distinguish different objects, etc., and do not represent a sequence, nor do they limit the "first", "second" and "third" to different types.

[0144] In the description of the embodiments of this application, the words "exemplary," "for example," or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary," "for example," or "for example" in the embodiments of this application should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary," "for example," or "for example" is intended to present the relevant concepts in a concrete manner.

[0145] In the description of the embodiments of the present application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; “and / or” in the text is merely a description of the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, “multiple” refers to two or more than two.

[0146] In some processes described in the embodiments of the present application, multiple operations or steps are included that appear in a specific order. However, it should be understood that these operations or steps may not be performed in the order in which they appear in the embodiments of the present application or may be performed in parallel. The sequence numbers of the operations are only used to distinguish between different operations, and the sequence numbers themselves do not represent any order of execution. In addition, these processes may include more or fewer operations, and these operations or steps may be performed in sequence or in parallel, and these operations or steps may be combined.

[0147] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus the necessary general hardware platform, of course, it can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes a number of instructions for enabling a terminal device to execute the methods described in each embodiment of the present application.

[0148] The above are only preferred embodiments of the present application and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the description and drawings of this application, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A fuel cell stack water balance test method, characterized in that: The fuel cell stack water balance test method includes: When the current output by the proton exchange membrane fuel cell stack is controlled to be the reference current, the following steps are performed at intervals of a preset duration: Lower the operating temperature of the battery stack to reduce the average single-chip voltage; detecting whether the decay rate of the average single-chip voltage reaches a first threshold; If the decay rate of the average single-chip voltage reaches a first threshold, obtaining a value of the stack operating temperature, and using the value of the stack operating temperature as the water balance critical temperature; and / or, When the current output by the proton exchange membrane fuel cell stack is controlled to be the reference current, the following steps are performed at intervals of a preset duration: Increase cathode humidity to reduce the average single-chip voltage; detecting whether the decay rate of the average single-chip voltage reaches a second threshold; If the decay rate of the average single-chip voltage reaches a second threshold, the value of the cathode humidity is obtained, and the value of the cathode humidity and the initial value of the anode humidity are used as the water balance critical humidity.

2. The fuel cell stack water balance test method according to claim 1, wherein: After the step of detecting whether the decay rate of the average single-chip voltage reaches a first threshold, the method further includes: If the decay rate of the average single-chip voltage does not reach the first threshold, determining whether the operating time reaches a preset time; If the operating time reaches the preset time, return to the step of lowering the operating temperature of the fuel cell stack; If the running time does not reach the preset time, the process returns to the step of detecting whether the decay rate of the average single-chip voltage reaches the first threshold.

3. The fuel cell stack water balance test method according to claim 1, wherein: After the step of detecting whether the decay rate of the average single-chip voltage reaches a second threshold, the method further includes: If the decay rate of the average single-chip voltage does not reach the second threshold, detecting whether the cathode humidity has reached a saturation value; If the cathode humidity has not reached the saturation value, determine whether the operating time has reached the preset time; If the running time reaches the preset time, return to the step of increasing the cathode humidity; If the running time does not reach the preset time, the process returns to the step of detecting whether the decay rate of the average single-chip voltage reaches the second threshold.

4. The fuel cell stack water balance test method according to claim 1, wherein: After the step of detecting whether the decay rate of the average single-chip voltage reaches a second threshold, the method further includes: If the decay rate of the average single-chip voltage does not reach the second threshold, detecting whether the cathode humidity has reached a saturation value; If the cathode humidity reaches the saturation value, the anode humidity is increased to reduce the average single-chip voltage; detecting whether the decay rate of the average single-chip voltage reaches a third threshold; If the decay rate of the average single-chip voltage reaches a third threshold, the value of the anode humidity is obtained, and the value of the anode humidity and the saturation value of the cathode humidity are used as the water balance critical humidity.

5. The fuel cell stack water balance test method according to claim 4, wherein: After the step of detecting whether the decay rate of the average single-chip voltage reaches a third threshold, the method further includes: If the decay rate of the average single-chip voltage does not reach the third threshold, detecting whether the anode humidity has reached a saturation value; If the anode humidity has not reached the saturation value, determine whether the operating time has reached the preset time; If the running time reaches the preset time, return to the step of increasing the anode humidity; If the running time does not reach the preset time, the process returns to the step of detecting whether the decay rate of the average single-chip voltage reaches the third threshold.

6. The fuel cell stack water balance test method according to claim 4, wherein: After the step of detecting whether the decay rate of the average single-chip voltage reaches a third threshold, the method further includes: If the decay rate of the average single-chip voltage does not reach the third threshold, detecting whether the anode humidity has reached a saturation value; If the anode humidity reaches the saturation value, the cathode stoichiometric ratio is reduced to reduce the average single-chip voltage; detecting whether the decay rate of the average single-chip voltage reaches a fourth threshold; If the decay rate of the average single-chip voltage reaches a fourth threshold, the saturation value of the cathode humidity and the saturation value of the anode humidity are used as the water balance critical humidity.

7. A fuel cell stack water balance test device, characterized in that: The fuel cell stack water balance test device comprises: The first execution module is configured to, while controlling the current output by the proton exchange membrane fuel cell stack to be a reference current, execute the following steps at intervals of a preset duration: lowering the stack operating temperature to reduce the average single-cell voltage; detecting whether the decay rate of the average single-cell voltage reaches a first threshold; if the decay rate of the average single-cell voltage reaches the first threshold, obtaining a value of the stack operating temperature, and using the value of the stack operating temperature as a water balance critical temperature; and / or, The second execution module is used to perform the following steps at each preset time interval while controlling the current output by the proton exchange membrane fuel cell stack to be a reference current: increasing the cathode humidity to reduce the average single-chip voltage; detecting whether the attenuation rate of the average single-chip voltage reaches a second threshold; if the attenuation rate of the average single-chip voltage reaches the second threshold, obtaining the numerical value of the cathode humidity, and using the numerical value of the cathode humidity and the initial value of the anode humidity as the water balance critical humidity.

8. The fuel cell stack water balance test device according to claim 7, characterized in that: The fuel cell stack water balance test device further includes a first detection module, which is specifically configured to, after the step of detecting whether the decay rate of the average single-cell voltage reaches a first threshold, determine whether the operating time reaches a preset time if the decay rate of the average single-cell voltage does not reach the first threshold; If the operating time reaches the preset time, return to the step of lowering the operating temperature of the fuel cell stack; If the running time does not reach the preset time, the process returns to the step of detecting whether the decay rate of the average single-chip voltage reaches the first threshold.

9. A fuel cell stack water balance test device, characterized in that: The fuel cell stack water balance test device includes a processor, a memory, and a fuel cell stack water balance test program stored in the memory and executable by the processor, wherein when the fuel cell stack water balance test program is executed by the processor, the steps of the fuel cell stack water balance test method as described in any one of claims 1 to 6 are implemented.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a fuel cell stack water balance test program, wherein when the fuel cell stack water balance test program is executed by the processor, the steps of the fuel cell stack water balance test method according to any one of claims 1 to 6 are implemented.

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